1. Field of the Invention
The present invention relates to a device for measuring the similarity between images and a method used by the same, and more particularly, to a method and device for accurately measuring the similarity between images.
2. Description of the Related Art
For applications of image search and retrieval, the characterization of the statistical attribute of textures is widely used. Texture descriptors are obtained according to such characterization. A texture descriptor is composed of two components: a similarity retrieval component (SRC) based on statistics and a perceptual browsing component (PBC) which is developed for describing the perceptual attributes of textures, such as the directionality and the texture's regularity. Such a texture descriptor is used for browsing and classifying images. The browsing and classifying of images are based on a measure of a distance. The measure of a distance is defined based on a feature vector and provides the similarity/dissimilarity between images.
A conventional similarity measuring method uses a statistical-based texture descriptor. According to this method, when the radius of a sphere centered at the feature vector of a query image is expanded in a feature vector space, if other feature vectors fall within the sphere, it is determined that the possibility that the query image is perceptually similar to the texture features of images corresponding to the feature vectors is very high.
However, for images corresponding to feature vectors newly falling within the sphere when the radius of the sphere is continuously increased in such a conventional similarity measuring method, the possibility that they are perceptually similar to the query image drops rapidly. Accordingly, the conventional similarity measuring method using a statistical-based texture descriptor has a problem in that an image which has been retrieved as being perceptually similar to a query image may not have a perceptual similarity to the query image.